An elevating work platform conventionally consists of a base, an extending structure (for example a boom or other lifting structure) mounted on the base that may be articulated and/or telescopic, and an operator cage that is attached to the end of the extending structure. The operator cage provides the operator with an enclosed and protected area in which to stand while operating the machine. The cage also provides the operator with a platform from which to work when the cage is elevated. The base may be either static or mobile.
A safety hazard can occur both during operation of the platform and also when a MEWP is driven, as the operator may not notice an overhead obstruction and may be pressed against the control console, which in turn could lead to injury or death. Similar risks may also arise in other machines, for example telehandlers and forklifts, in which an operator cage is fitted as an attachment to the load-bearing forks.
An operator cage system that addresses this safety issue is described in international patent application WO2009/037429A, in which the control console is protected by a system that detects a force applied to the console, or to a displaceable handrail or support in the vicinity of the console. If the operator is pressed against the console, this activates a safety switch, which in turn interrupts the drive system of the lifting mechanism (and, if applicable, of the wheels) to prevent further movement of the cage, thus avoiding serious injury to the operator.
A problem with this system is that the operator is unable to override the safety system and must therefore rely on others to rescue him or her from being trapped. If a rescuer is not present, the operator may remain trapped for some considerable time.
It is an object of the present invention to provide an operator cage that mitigates at least some of the aforesaid disadvantages.